Retail sales dropped 2.0 percent in September from the same month a year ago to 10.57 trillion yen, extending the streak of year-on-year declines to a record 30 months, according to a preliminary report issued Wednesday by the Ministry of International Trade and Industry.

Wholesalers saw sales decline 6.8 percent to 40.79 trillion yen due to sluggish exports of ships, office machinery and automobiles, and deflationary wholesale prices.

Commodities dealt in by trading firms and agricultural products and construction materials suffered the most, the report says.

Overall commercial sales were 51.36 trillion yen, down 5.9 percent from the same month a year ago, extending the string of consecutive year-on-year declines to 27 months.

Taking the decline in consumer prices into account, however, retail sales could actually be seen as improving in September, thanks to lingering summer heat and bargain sales celebrating the pennant won by the Fukuoka Daiei Hawks, MITI officials said.

While supermarkets benefited from the summer heat to expand sales 6.5 percent on a year-on-year basis, department stores suffered a decline of 5.5 percent because of sluggish sales of fall clothing.

MITI officials said sales have been see-sawing and will likely be flat in the future.